This invention was developed primarily to limit the intensity amplitude excursions of pulsed gas lasers in the infrared region. These laser types have notoriously poor amplitude control, the best variation being approximately 30% pulse to pulse. Present methods for stabilizing the output of these devices consists in careful design of the pump source so that equal power is applied for each pulse. However, due to the statistical nature of population inversion mechanism, the inverted population is very seldom the same, giving rise to different numbers of light quanta radiated from the device. Even the best efforts of amplitude stabilization still result in approximately 5% amplitude variations of the radiation output. This invention can limit the amplitude variation to 0.1% or less. This small amplitude variation is necessary where the pulsed laser is to be used as an analytical probe laser to determine the gain of an optically active medium.